1. Field of the Invention
The present invention relates to a roll for transporting workpieces in heated environments, more particularly, the present invention relates to a water-cooled roll for a roller hearth furnace.
2. Background Information
A variety of water-cooled roll designs have been proposed. For example, U.S. Pat. Nos. 5,379,829; 5,082,047; and 4,991,276 all disclose a water-cooled roll design with a xe2x80x9cflexiblexe2x80x9d arbor intended to bend and guide the workpiece. The tires are provided with extensions from one side thereof for attachment to the arbor. The tires are also provided with reduced section areas and openings to reduce heat flow from the work supporting surface of the tire to the arbor. These features combine to form a tire with a complex shape which is not easy to manufacture or assemble in the roll. A sample of earlier water-cooled roll designs are found in U.S. Pat. Nos. 2,085,575; 2,045,773; and 3,860,387.
These existing devices do not provide a simplified water-cooled roll design which is cost-effective to manufacture and still sufficiently minimize the heat flow from the work contacting surface to the arbor. It is the object of the present invention to overcome the aforementioned drawbacks of the prior art.
The above objects are achieved with a water-cooled roll according to the present invention. The roll includes a hollow rotatable arbor with a system for supplying cooling water to the interior of the arbor. A plurality of annular tires are spaced along the arbor, with each tire including a plurality of recesses spaced along an inner periphery of the tire on opposite sides of the tire. A plurality of locking bars are attached to the arbor, each locking bar extending into one recess of one tire. Each tire includes at least two locking bars extending into recesses thereof for rotationally and axially positioning the tire on the arbor.
In one embodiment of the present invention an annular body of each tire is tapered radially inwardly from the outermost work contacting surface to a position of the recesses. The recesses on one side of the annular body may be angularly offset from the recesses on the other side of the annular body. For example, the recesses on one side of the annular body may be offset from each other by about 90 degrees and the recesses on one side of the annular body may be offset from the recesses on the other side of the annular body by about 45 degrees. In one embodiment of the present invention, each recess has a pair of generally planar abutment walls and a substantially planar back wall, each adapted to abut against a locking bar.
In one embodiment of the present invention, the system for supplying cooling water to the arbor includes a water supply pipe positioned within the arbor, spaced from the inner walls thereof by a plurality of spacers on an outer periphery of the pipe to create an annular space therebetween. In order to position the pipe within the arbor, an end cap may be secured to one end of the arbor and a pipe end holder may extend into the arbor at an opposite end of the arbor with the pipe end holder coupled to the pipe.
These and other advantages of the present invention will be clarified in the description of the preferred embodiments taken together with the attached figures wherein like reference numerals represent like elements throughout.